JP4151835B2 - Modified polymer, method for producing the same, and rubber composition - Google Patents

Description

【００１５】
（式中、Ｒ^１及びＲ^２は、それぞれ炭素数１〜１８の一価の炭化水素基、ｎは１〜３の整数を示し、Ｒ^１Ｏが複数ある場合、各Ｒ^１Ｏはたがいに同一でも異なっていてもよく、Ｒ^２Ｏが複数ある場合、各Ｒ^２Ｏはたがいに同一でも異なっていてもよい。）
で表されるヒドロカルビルオキシシリル基である。
上記一般式（II）において、Ｒ¹及びＲ²は、それぞれ炭素数１〜１８の一価の炭化水素基を示す。この一価の炭化水素基としては、例えば炭素数１〜１８のアルキル基，炭素数２〜１８のアルケニル基，炭素数６〜１８のアリール基，炭素数７〜１８のアラルキル基などを挙げることができる。ここで、上記アルキル基及びアルケニル基は直鎖状，枝分かれ状，環状のいずれであってもよく、その例としては、メチル基，エチル基，ｎ−プロピル基，イソプロピル基，ｎ−ブチル基，イソブチル基，ｓｅｃ−ブチル基，ｔｅｒｔ−ブチル基，ペンチル基，ヘキシル基，オクチル基，デシル基，ドデシル基，シクロペンチル基，シクロヘキシル基，ビニル基，プロぺニル基，アリル基，ヘキセニル基，オクテニル基，シクロペンテニル基，シクロヘキセニル基などが挙げられる。
【００１６】
また、該アリール基は、芳香環上に低級アルキル基などの置換基を有していてもよく、その例としては、フェニル基，トリル基，キシリル基，ナフチル基などが挙げられる。さらに該アラルキル基は、芳香環上に低級アルキル基などの置換基を有していてもよく、その例としては、ベンジル基，フェネチル基，ナフチルメチル基などが挙げられる。
ｎは１〜３の整数を示し、Ｒ¹Ｏが複数ある場合、各Ｒ¹Ｏはたがいに同一でも異なっていてもよく、Ｒ²が複数ある場合、各Ｒ²はたがいに同一でも異なっていてもよい。
【００１７】
前記一般式（Ｉ）で表わされるプロトン性官能基含有化合物の例としては、Ｎ−メチルアミノプロピルメトキシシラン、Ｎ−（３−トリエトキシプロピル）アセトアミド及びこれらのトリエトキシシリル化合物に対応するトリメトキシシリル化合物，メチルジエトキシシリル化合物，エチルジエトキシシリル化合物，メチルジメトキシシリル化合物，エチルジメトキシシリル化合物などが好ましく挙げられるが、これらの中で特に、Ｎ−メチルアミノプロピルトリメトキシシラン、Ｎ−（３−トリエトキシプロピル）アセトアミドが好適である。
さらに、プロトン性官能基含有化合物の他の例として、Ｎ−ヒドロキシエチル−Ｎ−メチルアミノプロピルトリメトキシシラン，３−メルカプトプロピルトリエトキシシラン，Ｎ−５−トリメトキシシリルプロピル−２−アザ−１−オキソ−カプロラクタム、Ｎ−（２−アミノエチル）−２−アミノプロピルトリエトキシシラン，ウレイドプロピルトリメトキシシランなどが挙げられる。
また、本発明において、前記のプロトン性官能基化合物との反応に用いられる有機リチウム化合物（Ｂ）としては、後述のジエン系重合体の重合に用いられる重合開始剤としてのリチウム化合物と同種のものを使用することができる。
【００１８】
次に、本発明の製造方法において、予め調製された変性剤は、アニオン重合で合成された重合体の該活性部位と反応させることが必要である。この際、重合体の活性末端は、リチウム化されたプロトン性官能基とは反応せず、前記一般式（II）の化合物(変性剤)中のＸ^１基と反応して中間変性体を生成する。
上記で用いられる有機金属型の活性部位を分子中に有する重合体の製造方法については特に制限はなく、溶液重合法、気相重合法、バルク重合法のいずれも用いることができるが、特に溶液重合法が好ましい。また、重合形式は、回分式及び連続式のいずれであってもよい。
【００１９】
また、前記活性部位の金属はアルカリ金属及びアルカリ土類金属から選ばれる１種であることが好ましく、特にリチウム金属が好ましい。
上記溶液重合法においては、例えばリチウム化合物を重合開始剤とし、ジエン化合物単独又はジエン化合物と芳香族ビニル化合物をアニオン重合させることにより、目的の重合体を製造することができる。
なお、前記活性部位は重合体の分子中に存在すればよく、特に限定されないが、重合体がアルカリ金属化合物及び／又はアルカリ土類金属化合物を重合開始剤としたアニオン重合によるものである場合には、一般的に前記活性部位は重合体の末端にくる。
【００２０】
上記ジエン化合物としては、共役ジエン化合物が好ましく、例えば１，３−ブタジエン；イソプレン；１，３−ペンタジエン；２，３−ジメチルブタジエン；２−フェニル−１，３−ブタジエン；１，３−ヘキサジエンなどが挙げられる。これらは単独で用いてもよく、二種以上を組み合わせて用いてもよいが、これらの中で、１，３−ブタジエン、イソプレンが特に好ましい。
また、これらの共役ジエン化合物との共重合に用いられる芳香族ビニル化合物としては、例えばスチレン；α−メチルスチレン；１−ビニルナフタレン；３−ビニルトルエン；エチルビニルベンゼン；ジビニルベンゼン；４−シクロヘキシルスチレン；２，４，６−トリメチルスチレンなどが挙げられる。これらは単独で用いてもよく、二種以上を組み合わせて用いてもよいが、これらの中で、スチレンが特に好ましい。
【００２１】
さらに、単量体として共役ジエン化合物と芳香族ビニル化合物を用いて共重合を行う場合、それぞれ１，３−ブタジエン及びスチレンの使用が、単量体の入手の容易さなどの実用性の面、及びアニオン重合特性がリビング性などの点で優れることなどから、特に好適である。
また、溶液重合法を用いた場合には、溶媒中の単量体濃度は、好ましくは５〜５０重量％、より好ましくは１０〜３０重量％である。尚、共役ジエン化合物と芳香族ビニル化合物を用いて共重合を行う場合、仕込み単量体混合物中の芳香族ビニル化合物の含量は好ましくは３〜５０重量％、さらには５〜４５重量％の範囲が好ましい。
【００２２】
重合開始剤のリチウム化合物としては、特に制限はないが、ヒドロカルビルリチウム及びリチウムアミド化合物が好ましく用いられ、前者のヒドロカルビルリチウムを用いる場合には、重合開始末端にヒドロカルビル基を有し、かつ他方の末端が重合活性部位である共役ジエン系重合体が得られる。また、後者のリチウムアミド化合物を用いる場合には、重合開始末端に窒素含有基を有し、他方の末端が重合活性部位である共役ジエン系重合体が得られる。
上記ヒドロカルビルリチウムとしては、炭素数２〜２０のヒドロカルビル基を有するものが好ましく、例えばエチルリチウム、ｎ−プロピルリチウム、イソプロピルリチウム、ｎ−ブチルリチウム、ｓｅｃ−ブチルリチウム、ｔｅｒｔ−オクチルリチウム、ｎ−デシルリチウム、フェニルリチウム、２−ナフチルリチウム、２−ブチル−フェニルリチウム、４−フェニル−ブチルリチウム、シクロヘキシルリチウム、シクロペンチルリチウム、ジイソプロペニルベンゼンとブチルリチウムとの反応生成物などが挙げられるが、これらの中で、ｎ−ブチルリチウムが好ましい。
【００２３】
一方、リチウムアミド化合物としては、例えばリチウムヘキサメチレンイミド、リチウムピロリジド、リチウムピペリジド、リチウムヘプタメチレンイミド、リチウムドデカメチレンイミド、リチウムジメチルアミド、リチウムジエチルアミド、リチウムジブチルアミド、リチウムジプロピルアミド、リチウムジヘプチルアミド、リチウムジヘキシルアミド、リチウムジオクチルアミド、リチウムジ−２−エチルヘキシルアミド、リチウムジデシルアミド、リチウム−Ｎ−メチルピペラジド、リチウムエチルプロピルアミド、リチウムエチルブチルアミド、リチウムメチルブチルアミド、リチウムエチルベンジルアミド、リチウムメチルフェネチルアミドなどが挙げられる。これらの中で、カーボンブラックに対する相互作用効果及び重合開始能などの点から、リチウムヘキサメチレンイミド、リチウムピロリジド、リチウムピペリジド、リチウムヘプタメチレンイミド、リチウムドデカメチレンイミドなどの環状リチウムアミドが好ましく、特にリチウムヘキサメチレンイミド及びリチウムピロリジドが好適である。
【００２４】
これらのリチウムアミド化合物は、一般に、二級アミンとリチウム化合物とから、予め調製したものを重合に使用することが多いが、重合系中（ｉｎ−ｓｉｔｕ）で調製することもできる。また、この重合開始剤の使用量は、好ましくは単量体１００ｇ当たり、０．２〜２０ミリモルの範囲で選定される。
前記リチウム化合物を重合開始剤として用い、アニオン重合によって共役ジエン系重合体を製造する方法としては、特に制限はなく、従来公知の方法を用いることができる。
具体的には、反応に不活性な有機溶剤、例えば脂肪族、脂環族、芳香族炭化水素化合物などの炭化水素系溶剤中において、共役ジエン化合物又は共役ジエン化合物と芳香族ビニル化合物を、前記リチウム化合物を重合開始剤として、所望により、用いられるランダマイザーの存在化にアニオン重合させることにより、目的の共役ジエン系重合体が得られる。
【００２５】
前記炭化水素系溶剤としては、炭素数３〜８のものが好ましく、例えばプロパン、ｎ−ブタン、イソブタン、ｎ−ペンタン、イソペンタン、ｎ−ヘキサン、シクロヘキサン、プロペン、１−ブテン、イソブテン、トランス−２−ブテン、シス−２−ブテン、１−ペンテン、２−ペンテン、１−ヘキセン、２−ヘキセン、ベンゼン、トルエン、キシレン、エチルベンゼンなどを挙げることができる。これらは単独で用いてもよく、二種以上を混合して用いてもよい。
また、所望により用いられるランダマイザーとは、共役ジエン重合体のミクロ構造の制御、例えばブタジエン−スチレン共重合体におけるブタジエン部分の１、２結合、イソプレン重合体における３、４結合の増加など、あるいは共役ジエン化合物−芳香族ビニル化合物共重合体における単量体単位の組成分布の制御、例えばブタジエン−スチレン共重合体におけるブタジエン単位、スチレン単位のランダム化などの作用を有する化合物のことである。このランダマイザーとしては、特に制限はなく、従来ランダマイザーとして一般に使用されている公知の化合物の中から任意のものを適宜選択して用いることができる。具体的には、ジメトキシベンゼン、テトラヒドロフラン、ジメトキシエタン、ジエチレングリコールジブチルエーテル、ジエチレングリコールジメチルエーテル、ビステトラヒドロフリルプロパン、トリエチルアミン、ピリジン、Ｎ−メチルモルホリン、Ｎ，Ｎ，Ｎ’，Ｎ’−テトラメチルエチレンジアミン、１，２−ジピペリジノエタンなどのエーテル類及び第三級アミン類などを挙げることができる。また、カリウム−ｔ−アミレート、カリウム−ｔ−ブトキシドなどのカリウム塩類、ナトリウム−ｔ−アミレートなどのナトリウム塩類も用いることができる。
これらのランダマイザーは、一種を単独で用いてもよく、二種以上を組み合わせて用いてもよい。また、その使用量は、リチウム化合物１モル当たり、好ましくは０．０１〜１０００モル当量の範囲で選択される。
【００２６】
この重合反応における温度は、好ましくは０〜１５０℃、より好ましくは２０〜１３０℃の範囲で選定される。重合反応は、発生圧力下で行うことができるが、通常は単量体を実質的に液相に保つに十分な圧力で操作することが望ましい。すなわち、圧力は重合される個々の物質や、用いる重合媒体及び重合温度にもよるが、所望ならばより高い圧力を用いることができ、このような圧力は重合反応に関して不活性なガスで反応器を加圧する等の適当な方法で得られる。
この重合においては、重合開始剤、溶媒、単量体など、重合に関与する全ての原材料は、水、酸素、二酸化炭素、プロトン性化合物などの反応阻害物質を除去したものを用いることが望ましい。
なお、エラストマーとして重合体を得る場合は、得られる重合体又は共重合体の、示差熱分析法により求めたガラス転移点（Ｔｇ）が−９０℃〜−１５℃であることが好ましい。ガラス転移点が−９０℃未満の重合体を得るのは困難であり、また−１５℃を超える場合には室温領域で粘度が高くなりすぎ、取り扱いが困難となる場合がある。
【００２７】
本発明における前記変性剤は、得られた有機金属型の活性部位を分子中に有する重合体に対して、好ましくは該活性部位に対する化学量論的量又はそれより過剰を加えて反応させる。
このようにして得られた中間変性重合体は、最終工程において、リチウム化部位からリチウムを離脱し活性プロトンを再生する必要がある。このような活性プロトンを再生は、例えばアルコールや水と処理することで容易に行なうことができ、通常の脱溶媒、乾燥過程におけるスチームストリッピング工程で同時に、中間変性重合体において活性プロトンを再生させることができる。
本発明においては、上記の方法により変性重合体を製造することができるが、下記に、変性剤としてＮ−メチルアミノプロピルトリメトキシシラン（ＭＡＰＭＯＳ）を用いた場合を例にとり、本発明の変性重合体の製造方法における反応機構を説明する。
【００２８】
【化３】

【００２９】
【化４】

【００３０】
上記において、まずＭＡＰＭＯＳに、ブチルリチウム（ＢｕＬｉ）を作用させると、ＭＡＰＭＯＳ中アミノ基の活性プロトンは、Ｂｕアニオンに引き抜かれてＭＡＰＭＯＳのリチウム塩(Ａ’)となり、次に、該リチウム塩(Ａ’)を重合体の活性末端（Ｍ⁺は活性金属）と反応させた後で、水などと作用させることにより活性プロトンを有するアミノ基が再生する。本発明における変性重合体はこのような反応機構により得られる。
本発明においては、この変性反応時に、所望により、公知の老化防止剤や重合反応を停止する目的でショートストップ剤を、重合体の活性部位に変性剤の化合物残基を導入した後の工程において、添加することができる。
このようにして変性処理したのち、脱溶媒などの従来公知の後処理を行い、目的の変性重合体を得ることができる。この変性重合体の重合鎖活性部位変性基の分析は、高速液体クロマトグラフィー（ＨＰＬＣ）や、核磁気共鳴分光（ＮＭＲ）を用いて行うことができる。
【００３１】
また、該変性重合体のムーニー粘度（ＭＬ_１＋４，１００℃）は、好ましくは１０〜１５０、より好ましくは１５〜８０である。ムーニー粘度が１０未満の場合は破壊特性を始めとするゴム物性が十分に得られず、１５０を超える場合は作業性が悪く配合剤とともに混練りすることが困難である。
本発明において、このようにして得られた変性重合体は、末端に活性プロトンを有しているので、これにカーボンブラックを配合した場合には、カーボンブラック表面の官能基との水素結合により、その分散性と補強性を大幅させることができる。また、変性剤が、例えば前記一般式（II）で表わされるヒドロカルビルオキシシラン化合物残基を併有する場合には、同時にシリカとの親和性も大きい。
従って、本発明における変性重合体を、シリカ及び/又はカーボンブラックの配合系のゴム組成物に適用した場合には、シリカ及び/又はカーボンブラックとの相互作用を高め、破壊特性、耐摩耗性及び低発熱性を同時に向上させるとともに、良好に作業性を発揮し得る変性重合体、これを用いたゴム組成物およびタイヤを得ることができる。
そこで、本発明は、アニオン重合により合成した共役ジエン系重合体の末端部位に、窒素，酸素又はイオウに結合する水素を活性プロトンとするプロトン性官能基を含有する変性重合体を構成とするものでもある。
【００３２】
次に、本発明のゴム組成物は、上記変性重合体を含むものであり、通常、該変性重合体を少なくとも３０重量％を含むゴム成分と、その１００重量部当たり、シリカ及び／又はカーボンブラック１０〜１００重量部を含むゴム組成物が好ましい。
この変性重合体は一種用いてもよく、二種以上を組み合わせて用いてもよい。また、この変性重合体と併用されるゴム成分としては、天然ゴム及びジエン系合成ゴムが挙げられ、ジエン系合成ゴムとしては、例えばスチレン−ブタジエン共重合体（ＳＢＲ）、ポリブタジエン（ＢＲ）、ポリイソプレン（ＩＲ）、ブチルゴム（ＩＩＲ）、エチレン−プロピレン共重合体及びこれらの混合物等が挙げられる。また、その一部が多官能型変性剤、例えば四塩化スズのような変性剤を用いることにより分岐構造を有しているものでもよい。
【００３３】
上記シリカとしては特に制限はなく、従来ゴムの補強用充填材として慣用されているものの中から任意に選択して用いることができる。
このシリカとしては、例えば湿式シリカ（含水ケイ酸）、乾式シリカ（無水ケイ酸）、ケイ酸カルシウム、ケイ酸アルミニウム等が挙げられるが、中でも破壊特性の改良効果並びにウェットグリップ性の両立効果が最も顕著である湿式シリカが好ましい。一方、カーボンブラックとしては特に制限はなく、従来ゴムの補強用充填材として慣用されているものの中から任意のものを選択して用いることができる。このカーボンブラックとしては、例えばＦＥＦ，ＳＲＦ，ＨＡＦ，ＩＳＡＦ，ＳＡＦ等が挙げられる。好ましくはヨウ素吸着量（ＩＡ）が６０ｍｇ／ｇ以上で、かつ、ジブチルフタレート吸油量（ＤＢＰ）が８０ミリリットル／１００ｇ以上のカーボンブラックである。このカーボンブラックを用いることにより、諸物性の改良効果は大きくなるが、特に、耐摩耗性に優れるＨＡＦ，ＩＳＡＦ，ＳＡＦが好ましい。
【００３４】
本発明のゴム組成物においては、補強用充填材としてシリカを用いる場合、その補強性をさらに向上させる目的で、シランカップリッグ剤を配合することができる。このシランカップリング剤としては、例えばビス（３−トリエトキシシリルプロピル）テトラスルフィド、ビス（３−トリエトキシシリルプロピル）トリスルフィド、ビス（３−トリエトキシシリルプロピル）ジスルフィド、ビス（２−トリエトキシシリルエチル）テトラスルフィド、ビス（３−トリメトキシシリルプロピル）テトラスルフィド、ビス（２−トリメトキシシリルエチル）テトラスルフィド、３−メルカプトプロピルトリメトキシシラン、３−メルカプトプロピルトリエトキシシラン、２−メルカプトエチルトリメトキシシラン、２−メルカプトエチルトリエトキシシラン、３−トリメトキシシリルプロピル−Ｎ、Ｎ−ジメチルチオカルバモイルテトラスルフィド、３−トリエトキシシリルプロピル−Ｎ、Ｎ−ジメチルチオカルバモイルチトラスルフィド、２−トリエトキシシリルエチル−Ｎ、Ｎ−ジメチルチオカルバモイルテトラスルフィド、３−トリメトキシシリルプロピルベンゾチアゾールテトラスルフィド、３−トリエトキシシリルプロピルベンゾチアゾリルテトラスルフィド、３−トリエトキシシリルプロピルメタクリレートモノスルフィド、３−トリメトキシシリルプロピルメタクリレートモノスルフィド、ビス（３−ジエトキシメチルシリルプロピル）テトラスルフィド、３−メルカプトプロピルジメトキシメチルシラン、ジメトキシメチルシリルプロピル−Ｎ、Ｎ−ジメチルチオカルバモイルテトラスルフィド、ジメトキシメチルシリルプロピルベンゾチアゾールテトラスルフィドなどが挙げられるが、これらの中で補強性改善効果などの点から、ビス（３−トリエトキシシリルプロピル）テトラスルフィド及び３−トリメトキシシリルプロピルベンゾチアゾリルテトラスルフィドが好適である。これらのシランカップリング剤は一種を単独で用いてもよく、二種以上を組み合わせて用いてもよい。
【００３５】
好ましいシランカップリング剤の配合量は、シランカップリング剤の種類などにより異なるが、シリカに対して、好ましくは１〜２０重量％の範囲で選定される。この量が１重量％未満ではカップリング剤としての効果が充分に発揮されにくく、また、２０重量％を超えるとゴム成分のゲル化を引き起こすおそれがある。カップリング剤としての効果及びゲル化防止などの点から、このシランカップリング剤の好ましい配合量は、５〜１５重量％の範囲である。
本発明のゴム組成物には、本発明の目的が損なわれない範囲で、所望により、通常ゴム工業界で用いられる各種薬品、例えば加硫剤、加硫促進剤、プロセス油、老化防止剤、スコーチ防止剤、亜鉛華、ステアリン酸などを含有させることができる。
【００３６】
本発明のゴム組成物は、ロール、インターナルミキサー等の混練り機を用いて混練りすることによって得られ、成形加工後、加硫を行い、タイヤ用途を始め、防振ゴム，ベルト，ホースその他の工業品等の用途にも用いることができる。特にタイヤ用ゴムとして好適に使用され、例えばトレッドゴム（キャップゴム，ベースゴムを含む）、サイドゴム、プライゴム、ビードフィラーゴムなどあらゆるタイヤ部材に適用することができる。
本発明において、ゴム組成物を用いたタイヤは、低燃費性が良好であると共に、特に破壊特性及び耐摩耗性に優れており、しかも該ゴム組成物の加工性が良好であるので、生産性にも優れている。
【００３７】
【実施例】
次に、本発明を実施例によりさらに詳細に説明するが、本発明は、これらの例によってなんら限定されるものではない。
なお、重合体の物性は、下記の方法に従って測定した。
【００３８】
＜重合体の物性＞
（変性）重合体の重量平均分子量（Ｍｗ）の測定は、ゲルパーミエーションクロマトグラフィー〔ＧＰＣ；東ソ−製ＨＬＣ−８０２０、カラム；東ソ−製ＧＭＨ−ＸＬ（２本直列）〕により行い、示差屈折率（ＲＩ）を用いて、単分散ポリスチレンを標準としてポリスチレン換算で行った。
重合体のブタジエン部分のビニル量は、赤外法によって求め、重合体中のスチレン単位含有量は^１Ｈ−ＮＭＲスペクトルの積分比より算出した。
重合体のムーニー粘度は東洋精機社製のＲＬＭ−０１型テスターを用いて、１００℃で測定した。
【００３９】
＜加硫ゴムの物性＞
（１）低発熱性
粘弾性測定装置（レオメトリックス社製）を使用し、温度５０℃、歪み１０％、周波数１５Ｈｚでｔａｎδ（５０℃）を測定した。ｔａｎδ（５０℃）が小さい程、低発熱性である。
（２）破壊特性（引張り強力）
切断時の強力（Ｔ_ｂ）をＪＩＳ Ｋ６３０１−１９９５に従って測定した。
（３）耐摩耗性
ランボーン型摩耗試験機を用い、室温におけるスリップ率６０％の摩耗量を測定し、比較例４の耐摩耗性を１００として指数表示した。指数が大きい方が良好となる。
【００４０】
＜ゴム組成物のムーニー粘度＞
ＪＩＳ Ｋ６３００−１９９４に準拠し、１３０℃にてムーニー粘度〔ＭＬ_１＋４／１３０℃〕を測定した。
【００４１】
実施例１
（１）変性剤溶液の調製
乾燥し、窒素置換された３００ミリリットルの耐圧ガラス容器に、Ｎ−メチルアミノプロピルトリメトキシシラン（ＭＡＰＭＯＳ）の１規定シクロヘキサン溶液を調製し、ＭＡＰＭＯＳに当量となるように、ｎ−ブチルリチウム（ＢｕＬｉ）の３．６５規定シクロヘキサン溶液を滴下し、よく攪拌することにより、変性剤（Ｃ）の溶液を調製した。
（２）変性重合体の製造
乾燥し、窒素置換された８００ミリリットルの耐圧ガラス容器に、シクロヘキサン３００ｇ、１，３−ブタジエン単量体４０ｇ、スチレン単量体１０ｇ、ジテトラヒドロフリルプロパン０．４３ミリモルを注入し、これに０．４８ミリモルのｎ−ブチルリチウム（ＢｕＬｉ）を加えた後、５０℃で１．５時間重合を行った。重合転化率はほぼ１００％であった。
この重合系に（１）で調製した変性剤（Ｃ）の溶液を、Ｎ−メチルアミノプロピルトリメトキシシランが０．４３ミリモルとなるように加えた後に５０℃で３０分間変性反応を行なった。この後、２，６−ジ−ｔ−ブチル−ｐ−クレゾール（ＢＨＴ）のイソプロパノール５重量％溶液０．５ミリリットルを加えて反応の停止を行い、その後、常法に従いスチームストリッピングにより脱溶媒と乾燥を行ない、変性重合体Ｄを得た。得られた重合体の分析値を第１表に示す。
【００４２】
実施例２及び比較例１，２
実施例１の（１）変性剤溶液の調製において、変性剤であるＮ−メチルアミノプロピルトリメトキシシランの代わりに、第１表に示す種類の変性剤を用いた以外は、実施例１と同様にして重合体Ａ，Ｂ（各比較例）及びＥ（実施例）を得た。得られた各重合体の分析値を第１表に示す。
比較例３
実施例１において、変性剤溶液を用いなかったこと、及び（２）変性重合体の製造において、ＢｕＬｉの添加量を０．３８ミリモルとしたこと以外は、実施例１と同様にして重合体Ｃを得た。得られた重合体の分析値を第１表に示す。
実施例３
（１）変性剤溶液の調製
乾燥し、窒素置換された３００ミリリットルの耐圧ガラス容器に、Ｎ−メチルアミノプロピルトリメトキシシラン（ＭＡＰＭＯＳ）の１規定シクロヘキサン溶液を調製し、ＭＡＰＭＯＳに当量となるように、ｎ−ブチルリチウム（ＢｕＬｉ）の３．６５規定シクロヘキサン溶液を滴下した後、トリメチルシリルクロライド（ＴＭＳＣＬ）の１規定シクロヘキサン溶液を調製して、ＭＡＰＭＯＳと当量となるように加え、よく攪拌することにより、変性剤（Ｄ）の溶液を調製した。
（２）変性重合体の製造
実施例１の変性重合体の製造において、重合系に（１）で調製した変性剤（Ｄ）の溶液を加えたこと以外は、実施例１と同様にして行い、重合体Ｆを得た。得られた重合体の分析値を第１表に示す。
実施例４
実施例１の（１）変性剤溶液の調製において、変性剤であるＮ−メチルアミノプロピルトリメトキシシランの代わりに、３−メルカプトプロピルトリエトキシシランを用いたこと以外は、実施例１と同様にして重合体Ｇを得た。得られた各重合体の分析値を第１表に示す。
【００４３】
【表１】

【００４４】
（注）
Ｂａｓｅ Ｍｗ ；変性反応前の重量平均分子量（Ｍｗ）
Ｔｏｔａｌ Ｍｗ ；変性反応後の重量平均分子量（Ｍｗ）
変性剤
（比較例１）ＴＴＣ；四塩化スズ
（比較例２）ＴＥＯＳ；テトラエトキシシラン
（実施例１）ＭＡＰＭＯＳ；ＢｕＬｉを当量加えたＮ−メチルアミノプロピルトリメトキシシラン
（実施例２）ＴＥＯＳＡＡ；ＢｕＬｉを当量加えたＮ−（３−トリエトキシシリルプロピル）アセトアミド
（実施例３）ＭＡＰＭＯＳ ＆ ＴＭＣＬ；ＢｕＬｉを当量加えたＮ−メチルアミノプロピルトリメトキシシランとトリメチルシリルクロライドを反応
（実施例４）ＭｒＰＴＥＯＳ；ＢｕＬｉを当量加えた３−メルカプトプロピルトリエトキシシラン
【００４５】
実施例５〜８及び比較例４〜６（ゴム組成物）
実施例１〜４及び比較例１〜３で得られた重合体Ａ〜Ｇを用い、第２表に示す配合１及び配合２に従って、それぞれシリカ系配合のゴム組成物及びカーボンブラック系配合のゴム組成物を以下に示す方法により調製し、ゴム組成物のムーニー粘度を測定すると共に、１６０℃、１５分間の条件で加硫し、加硫ゴムの物性を測定した。その結果を第３表に示す。
【００４６】
【表２】

【００４７】
（注）
カーボンブラック ；東海カーボン(株)製「シーストＫＨ（Ｎ３３９）（商標）」
シリカ ；日本シリカ工業(株)製「ニプシルＡＱ（商標）」
カップリング剤 ；デグサ社製シランカップリング剤「Ｓｉ６９（商標）」、ビス（３−トリエトキシシリルプロピル）テトラスルフィド
老化防止剤６Ｃ ；Ｎ−（１，３−ジメチルブチル）−Ｎ’−フェニル−ｐ−フェニレンジアミン
加硫促進剤ＤＰＧ ；ジフェニルグアニジン
加硫促進剤ＤＭ ；メルカプトベンゾチアジルジスルフィド
加硫促進剤ＮＳ ；Ｎ−ｔ−ブチル−２−ベンゾチアジルスルフェンアミド
【００４８】
【表３】

【００４９】
【表４】

【００５０】
以上の結果、本発明の変性重合体は、シリカ系配合及びカーボンブラック系配合のいずれにおいても、ムーニー粘度の上昇を抑え、かつ破壊特性を損なうことなく、低発熱性及び耐摩耗性を著しく向上させていることが認められる。
【００５１】
【発明の効果】
本発明における変性重合体は、シリカ及び／又はカーボンブラックを配合したゴム組成物に適用した場合に、シリカ及び／又はカーボンブラックとの相互作用を高め、破壊特性、耐摩耗性及び低発熱性を同時に向上させると共に、良好な作業性を発揮し得る。また、本発明の方法によれば、前記優れた性能を有する特定変性重合体を容易に製造することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a modified polymer, a modifier, a modified polymer, a rubber composition and a tire using the modified polymer. More specifically, the present invention is a rubber composition containing silica and / or carbon black, which enhances the interaction with silica and carbon black, and simultaneously improves fracture characteristics, wear resistance and low heat build-up, and is good The present invention relates to a method for producing a modified polymer capable of exhibiting excellent workability, a modifier, a modified polymer, and a rubber composition and a tire using the modified polymer.
[0002]
[Prior art]
In recent years, due to social demands for energy saving, demands for lower fuel consumption of automobiles are becoming more severe. In order to meet such demands, a reduction in rolling resistance has also been demanded for tire performance. As a technique for reducing the rolling resistance of a tire, a technique by optimizing the tire structure has been studied, but the most common technique is to use a material with less heat generation as a rubber composition.
In order to obtain such a rubber composition with low heat generation, many technical developments have been made so far to improve the dispersibility of the filler used in the rubber composition. Among them, a method of modifying the polymerization active site of a diene polymer obtained by anionic polymerization using a lithium compound with a functional group that interacts with a filler is becoming the most common.
The most typical of such methods is a method in which carbon black is used as a filler and a polymerization active site is modified with a tin compound (Patent Document 1). A method of introducing a group (Patent Document 2) is known.
[0003]
On the other hand, in recent years, with increasing interest in safety of automobiles, not only low fuel consumption performance but also performance on wet road surfaces (hereinafter referred to as wet performance), in particular, braking performance has been increasing. For this reason, the performance requirement for the rubber composition of the tire tread is not limited to merely reducing the rolling resistance, but it is required to have a high balance between wet performance and low fuel consumption performance.
As a method for obtaining a rubber composition that gives tires such good fuel economy and good wet performance at the same time, silica is used in place of carbon black, which is a reinforcing filler generally used so far. The method is already done.
[0004]
However, it has also been clarified that when silica is used as a reinforcing filler, the fracture strength and wear resistance of the rubber composition are inevitably lowered as compared with carbon black. Further, the dispersibility of silica is poor, and the workability when kneading is also a big problem in actually manufacturing a tire.
Therefore, in order to obtain a rubber composition with good exothermic properties with high productivity, not only carbon black or silica is used alone as a reinforcing filler, but also silica and carbon black are used in combination. There is a need for an active site modified polymer that has a wide interaction with the filler and can provide good dispersibility of the filler and wear resistance of the rubber composition.
However, until now, active site-modified polymers have been developed for single fillers, so that site-modified polymers with sufficient interaction with various fillers, regardless of the type of filler. Is very limited. For example, the above-mentioned tin compound has a large dispersion effect on carbon black, but has almost no dispersion effect on silica and does not exhibit a reinforcing effect at all. Moreover, although there is a report on the dispersion effect of aminosilane on silica (Patent Document 3), the effect is not always sufficient.
[0005]
On the other hand, a method using an alkoxysilane having a silica dispersing effect and reinforcing effect improving effect is disclosed (Patent Document 4, Patent Document 5, Patent Document 6, etc.), but the effect is insufficient.
Further, a modified polymer in which an alkoxysilane having a dialkylamino group is introduced into the active terminal of a polymer obtained by anionic polymerization using alkyllithium or lithium amide as a polymerization initiator is disclosed (Patent Document 7). However, when this modified polymer is used, it is possible to obtain good workability, reinforcement to silica blending, and a certain dispersion effect on both silica and carpump racks, but the alkoxysilane having a dialkylamino group is expensive. Furthermore, a modified polymer using the same is also expensive and difficult to industrialize.
[0006]
By the way, the polymer having an active site used when producing a modified polymer is usually obtained by anionic polymerization of a conjugated diene compound alone or a conjugated diene compound and an aromatic vinyl compound. Introducing functional groups such as primary amino groups, secondary amino groups, and organic onium bases, which are thought to have a great effect on improving physical properties, to the active sites of polymers obtained by such anionic polymerization However, it was not easy due to the properties of anionic polymerization, and post-polymerization treatment under harsh conditions and expensive protective groups were required, and its industrial value was low.
[0007]
[Patent Document 1]
Japanese Patent Publication No. 5-87630 [Patent Document 2]
JP 62-207342 A [Patent Document 3]
JP-A-9-151275 (2nd page)
[Patent Document 4]
Japanese Patent Laid-Open No. 1-188501 (page 2)
[Patent Document 5]
JP-A-8-53513 (second page)
[Patent Document 6]
JP-A-8-53576 (2nd page)
[Patent Document 7]
Japanese Examined Patent Publication No. 6-57767 (2nd page)
[0008]
[Problems to be solved by the invention]
Under such circumstances, the present invention enhances the interaction with silica and / or carbon black when used in a rubber composition containing silica and / or carbon black, and has improved destructiveness, wear resistance and low heat build-up. A method for producing a modified polymer capable of simultaneously improving and exhibiting good workability, a modified polymer obtained by this method, a rubber composition containing this modified polymer, and a tire using the rubber composition It is intended to provide.
[0009]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventor, for example, a specific method capable of easily introducing a functional group having an active proton into an active site of a polymer synthesized by anionic polymerization. As a result, the present invention has been completed.
That is, the present invention relates to a method for producing a modified polymer by modifying a diene polymer, wherein (1) the general formula (I)
X ¹ -A ¹ -Y ¹ (I)
(In the formula, X ¹ is a monovalent organic group having a functional group that reacts with the active site of the diene polymer, and Y ¹ is a protic function having hydrogen as an active proton bonded to nitrogen, oxygen, or sulfur. A monovalent organic group having a group, and A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms.)
A protic functional group-containing compound (A) represented by the formula (A) is reacted with an organic alkali metal or alkaline earth metal compound (B), and the active proton in the protic functional group is converted to an alkali metal or alkaline earth metal A step of obtaining a modifying agent (C) by pretreatment, and (2) a weight for reacting the modifying agent (C) with the active site of a polymer having an organometallic active site obtained by, for example, anionic polymerization. Production of a modified polymer comprising: a step of obtaining an intermediate modified product of a coalescence; and (3) a step of releasing the metal from the metallization site of the obtained intermediate modified product to regenerate active protons. A method is provided.
[0010]
The present invention also relates to a method for producing a modified polymer by modifying a diene polymer, wherein (1) the general formula (I)
X ¹ -A ¹ -Y ¹ (I)
(In the formula, X ¹ , Y ¹ and A ¹ are the same as above.)
A protic functional group-containing compound (A) represented by the formula (A) is reacted with an organic alkali metal or alkaline earth metal compound (B), and the active proton in the protic functional group is converted to an alkali metal or alkaline earth metal (2) a step of further reacting the reaction product of the pretreatment with an alkylsilyl halide to obtain a modifier (D), and (3) the modifier (D), for example, anionic polymerization A step of obtaining an intermediate modified product of the polymer to be reacted with the active site of the polymer having an organometallic active site obtained by (4), and (4) removing the metal from the metallized site of the obtained intermediate modified product. The present invention provides a method for producing a modified polymer, which comprises a step of releasing and regenerating active protons.
Furthermore, the present invention is to provide the modifying agents (C) and (D), and also provides the modified polymer, a rubber composition containing the modified polymer, and a tire using the rubber composition. Is.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the first modifier used for the modification of the diene polymer is a reaction of a protic functional group-containing compound represented by the general formula (I) described below with an organic alkali metal or alkaline earth metal compound. Can be obtained. The second modifier is obtained by reacting the protic functional group-containing compound represented by the general formula (I) with an organic alkali metal or alkaline earth metal compound and further reacting with an alkylsilyl halide. It is done.
Here, since the second modifier is superior to the first modifier in stability over time, it is difficult to decompose, and since the reaction with the terminal active site of the polymer is easy, the second modifier is more effective than the first modifier. Preferably used.
The protic functional group-containing compound used as the raw material for the modifier must have a protic functional group and a functional group that reacts with the active site of a polymer having an organometallic active site. Therefore, the general formula (I)
X ¹ -A ¹ -Y ¹ (I)
(In the formula, X ¹ is a monovalent organic group having a functional group that reacts with the active site of the diene polymer, and Y ¹ is a protic function having hydrogen as an active proton bonded to nitrogen, oxygen, or sulfur. A monovalent organic group having a group, and A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms.)
And a protic functional group-containing compound represented by the formula:
By reacting this protic functional group-containing compound with an organic alkali metal or alkaline earth metal compound, a first modifier (C) is obtained, and this first modifier is further reacted with an alkylsilyl halide. Thus, the second modifier (D) can be obtained. As the alkylsilyl halide used for the production of the second modifier, for example, trimethylsilyl chloride is particularly preferred.
[0012]
In the formula (I), as the protic functional group Y ¹ has, specifically, a primary amine and its onium salt, a secondary amine and its onium salt, a primary amide, a secondary amide, and an acetylamide , Imino, carbamoyl, (thio) carboxyl, thiol, (thio) alcohol, carboxylic acid, (thio) ureido, (thio) carboxyl group, mercapto group, and the like. Among these, a functional group having an active proton (hydrogen) bonded to nitrogen is more preferable.
In the modified polymer production method of the present invention, as a first step, the protic functional group-containing modifier (A) represented by the general formula (I) is treated with an organic alkali metal or alkaline earth metal compound (B). ) To react with the active protons in the Y ¹ group to be alkyl metallized or alkyl earth metallized (substituted with alkyl metal or alkyl earth metal). When this pretreatment is not performed, active protons (active hydrogen) in the protic functional group of the modifier are extracted by the active site of the polymer, so that the protic functional group is introduced into the polymer as it is. I can't.
[0013]
Next, in the general formula (I), A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms. Examples of the divalent hydrocarbon group include an alkylene group having 1 to 20 carbon atoms, an alkenylene group having 2 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, and an aralkylene group having 7 to 20 carbon atoms. Among these, an alkylene group having 1 to 20 carbon atoms, particularly an alkylene group having 1 to 10 carbon atoms is preferable. The alkylene group may be linear, branched, or cyclic, but a linear one is particularly preferable. Examples of the linear alkylene group include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, an octamethylene group, and a decamethylene group.
Further, X ¹ in the general formula (I) is not particularly limited as long as it is a monovalent organic group having a functional group that reacts with the active site of the polymer, but the functional group that reacts with the active site of the polymer. Examples thereof include hydrocarbyloxy group, amino group, halogen, carbonyl group , hydrocarbyloxysilyl group, halide, imine, vinyl group, amide group and the like.
X ¹ is preferably represented by formula (II)
[0014]
[Chemical 2]

[0015]
(Wherein, ^{R 1} and ^{R 2} are each monovalent hydrocarbon group having 1 to 18 carbon atoms, n is an integer of 1 to 3, ^{when R 1} O is more, each ^{R 1} O is one another may be the same or different, when R 2 ^O is more, each R ^{2 O} may be the same or different.)
The hydrocarbyloxysilyl group represented by these.
In the general formula (II), R ¹ and R ² each represent a monovalent hydrocarbon group having 1 to 18 carbon atoms. Examples of the monovalent hydrocarbon group include an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, and an aralkyl group having 7 to 18 carbon atoms. Can do. Here, the alkyl group and alkenyl group may be linear, branched or cyclic, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, Isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl, cyclopentyl, cyclohexyl, vinyl, propenyl, allyl, hexenyl, octenyl , Cyclopentenyl group, cyclohexenyl group and the like.
[0016]
The aryl group may have a substituent such as a lower alkyl group on the aromatic ring, and examples thereof include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. Further, the aralkyl group may have a substituent such as a lower alkyl group on the aromatic ring, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.
n is an integer of 1 to 3, when R ¹ O is more, each R ¹ O may be the same as or different from each other, when R ² are a plurality, each R ² is the same with or different from each other May be.
[0017]
Examples of the protic functional group-containing compound represented by the general formula (I) include N-methylaminopropylmethoxysilane, N- (3-triethoxypropyl) acetamide, and trimethoxy corresponding to these triethoxysilyl compounds. Preferred examples include silyl compounds, methyldiethoxysilyl compounds, ethyldiethoxysilyl compounds, methyldimethoxysilyl compounds, and ethyldimethoxysilyl compounds. Among these, N-methylaminopropyltrimethoxysilane, N- (3 -Triethoxypropyl) acetamide is preferred.
Further, as other examples of the protic functional group-containing compound, N-hydroxyethyl-N-methylaminopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, N-5-trimethoxysilylpropyl-2-aza-1 -Oxo-caprolactam, N- (2-aminoethyl) -2-aminopropyltriethoxysilane, ureidopropyltrimethoxysilane and the like.
In the present invention, the organic lithium compound (B) used for the reaction with the protic functional group compound is the same as the lithium compound as a polymerization initiator used for polymerization of a diene polymer described later. Can be used.
[0018]
Next, in the production method of the present invention, it is necessary that the preliminarily prepared modifier is reacted with the active site of the polymer synthesized by anionic polymerization. In this case, the active end of the polymer does not react with the lithiated protic functional groups, generating an intermediate modified product by reacting with X ¹ group in said compound of general formula (II) (modifier) To do.
There is no particular limitation on the method for producing the polymer having an organometallic type active site in the molecule, and any of solution polymerization method, gas phase polymerization method and bulk polymerization method can be used. A polymerization method is preferred. Moreover, any of a batch type and a continuous type may be sufficient as the superposition | polymerization form.
[0019]
The metal of the active site is preferably one selected from alkali metals and alkaline earth metals, and lithium metal is particularly preferable.
In the solution polymerization method, for example, the target polymer can be produced by anionic polymerization of a diene compound alone or a diene compound and an aromatic vinyl compound using a lithium compound as a polymerization initiator.
The active site may be present in the polymer molecule, and is not particularly limited. However, when the polymer is based on anionic polymerization using an alkali metal compound and / or an alkaline earth metal compound as a polymerization initiator. In general, the active site is at the end of the polymer.
[0020]
The diene compound is preferably a conjugated diene compound, such as 1,3-butadiene; isoprene; 1,3-pentadiene; 2,3-dimethylbutadiene; 2-phenyl-1,3-butadiene; 1,3-hexadiene and the like. Is mentioned. These may be used alone or in combination of two or more, and among these, 1,3-butadiene and isoprene are particularly preferable.
Examples of the aromatic vinyl compound used for copolymerization with these conjugated diene compounds include styrene; α-methylstyrene; 1-vinylnaphthalene; 3-vinyltoluene; ethylvinylbenzene; divinylbenzene; 4-cyclohexylstyrene. 2,4,6-trimethylstyrene and the like. These may be used alone or in combination of two or more, but among these, styrene is particularly preferred.
[0021]
Furthermore, when copolymerization is performed using a conjugated diene compound and an aromatic vinyl compound as monomers, the use of 1,3-butadiene and styrene, respectively, in terms of practicality such as the availability of monomers, And anionic polymerization characteristics are particularly preferred in view of the living property.
When the solution polymerization method is used, the monomer concentration in the solvent is preferably 5 to 50% by weight, more preferably 10 to 30% by weight. When copolymerization is performed using a conjugated diene compound and an aromatic vinyl compound, the content of the aromatic vinyl compound in the charged monomer mixture is preferably 3 to 50% by weight, more preferably 5 to 45% by weight. Is preferred.
[0022]
The lithium compound of the polymerization initiator is not particularly limited, but hydrocarbyl lithium and lithium amide compounds are preferably used. When the former hydrocarbyl lithium is used, it has a hydrocarbyl group at the polymerization initiation terminal and the other terminal. A conjugated diene polymer having a polymerization active site is obtained. When the latter lithium amide compound is used, a conjugated diene polymer having a nitrogen-containing group at the polymerization initiation terminal and the other terminal being a polymerization active site is obtained.
As the hydrocarbyl lithium, those having a hydrocarbyl group having 2 to 20 carbon atoms are preferable, for example, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-octyl lithium, n-decyl. Examples include lithium, phenyl lithium, 2-naphthyl lithium, 2-butyl-phenyl lithium, 4-phenyl-butyl lithium, cyclohexyl lithium, cyclopentyl lithium, reaction products of diisopropenylbenzene and butyl lithium, and the like. Of these, n-butyllithium is preferred.
[0023]
On the other hand, as the lithium amide compound, for example, lithium hexamethylene imide, lithium pyrrolidide, lithium piperidide, lithium heptamethylene imide, lithium dodecamethylene imide, lithium dimethyl amide, lithium diethyl amide, lithium dibutyl amide, lithium dipropyl amide, lithium Diheptylamide, lithium dihexylamide, lithium dioctylamide, lithium di-2-ethylhexylamide, lithium didecylamide, lithium-N-methylpiperazide, lithium ethylpropylamide, lithium ethylbutyramide, lithium methylbutyramide, lithium ethylbenzylamide, Examples include lithium methyl phenethyl amide. Among these, cyclic lithium amides such as lithium hexamethylene imide, lithium pyrrolidide, lithium piperidide, lithium heptamethylene imide, and lithium dodecamethylene imide are preferable from the viewpoint of the interaction effect on carbon black and the ability to initiate polymerization. Particularly preferred are lithium hexamethylene imide and lithium pyrrolidide.
[0024]
These lithium amide compounds are generally prepared in advance from a secondary amine and a lithium compound for polymerization, but can also be prepared in a polymerization system (in-situ). The amount of the polymerization initiator used is preferably selected in the range of 0.2 to 20 mmol per 100 g of monomer.
There is no restriction | limiting in particular as a method of manufacturing a conjugated diene polymer by anionic polymerization using the said lithium compound as a polymerization initiator, A conventionally well-known method can be used.
Specifically, in an organic solvent inert to the reaction, for example, a hydrocarbon solvent such as an aliphatic, alicyclic or aromatic hydrocarbon compound, the conjugated diene compound or the conjugated diene compound and the aromatic vinyl compound are The desired conjugated diene polymer can be obtained by anionic polymerization using a lithium compound as a polymerization initiator in the presence of a randomizer to be used, if desired.
[0025]
The hydrocarbon solvent is preferably one having 3 to 8 carbon atoms, such as propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene and trans-2. -Butene, cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene and the like. These may be used alone or in combination of two or more.
The randomizer used as desired is a control of the microstructure of the conjugated diene polymer, such as an increase in 1,2 bonds in the butadiene moiety in the butadiene-styrene copolymer, an increase in 3,4 bonds in the isoprene polymer, or the like. It is a compound having an effect of controlling the composition distribution of monomer units in a conjugated diene compound-aromatic vinyl compound copolymer, for example, randomizing butadiene units and styrene units in a butadiene-styrene copolymer. The randomizer is not particularly limited, and any one of known compounds generally used as a conventional randomizer can be appropriately selected and used. Specifically, dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, bistetrahydrofurylpropane, triethylamine, pyridine, N-methylmorpholine, N, N, N ′, N′-tetramethylethylenediamine, 1, Examples include ethers such as 2-dipiperidinoethane and tertiary amines. Further, potassium salts such as potassium-t-amylate and potassium-t-butoxide, and sodium salts such as sodium-t-amylate can also be used.
One of these randomizers may be used alone, or two or more thereof may be used in combination. The amount used is preferably selected in the range of 0.01 to 1000 molar equivalents per mole of the lithium compound.
[0026]
The temperature in this polymerization reaction is preferably selected in the range of 0 to 150 ° C, more preferably 20 to 130 ° C. The polymerization reaction can be carried out under generated pressure, but it is usually desirable to operate at a pressure sufficient to keep the monomer in a substantially liquid phase. That is, the pressure depends on the particular material being polymerized, the polymerization medium used and the polymerization temperature, but higher pressures can be used if desired, such pressure being a gas that is inert with respect to the polymerization reaction. Can be obtained by an appropriate method such as pressurizing.
In this polymerization, it is desirable that all raw materials involved in the polymerization, such as a polymerization initiator, a solvent, and a monomer, are obtained by removing reaction inhibitors such as water, oxygen, carbon dioxide, and protic compounds.
In addition, when obtaining a polymer as an elastomer, it is preferable that the glass transition point (Tg) calculated | required by the differential thermal analysis method of the polymer or copolymer obtained is -90 degreeC--15 degreeC. It is difficult to obtain a polymer having a glass transition point of less than −90 ° C., and when it exceeds −15 ° C., the viscosity becomes too high in the room temperature region, which may make handling difficult.
[0027]
In the present invention, the modifying agent is reacted with the obtained polymer having an organometallic active site in the molecule, preferably by adding a stoichiometric amount or an excess of the active site.
The intermediate modified polymer thus obtained needs to regenerate active protons by removing lithium from the lithiation site in the final step. Such active protons can be easily regenerated by, for example, treatment with alcohol or water. At the same time, the active protons are regenerated in the intermediate modified polymer in the normal solvent removal and steam stripping steps in the drying process. be able to.
In the present invention, a modified polymer can be produced by the above-described method. The modified polymer of the present invention is exemplified below using N-methylaminopropyltrimethoxysilane (MAPMOS) as a modifier. The reaction mechanism in the method for producing the coalescence will be described.
[0028]
[Chemical 3]

[0029]
[Formula 4]

[0030]
In the above, first, when butyl lithium (BuLi) is allowed to act on MAPMOS, the active proton of the amino group in MAPMOS is extracted by Bu anion to become MAPMOS lithium salt (A ′), and then the lithium salt (A After reacting ') with the active terminal of the polymer (M ⁺ is an active metal), the amino group having active protons is regenerated by reacting with water or the like. The modified polymer in the present invention is obtained by such a reaction mechanism.
In the present invention, in this modification reaction, if desired, a known anti-aging agent or a short stop agent for the purpose of terminating the polymerization reaction, and a step after introducing a compound residue of the modifier in the active site of the polymer. , Can be added.
After the modification treatment in this way, a conventionally known post-treatment such as solvent removal can be performed to obtain the desired modified polymer. Analysis of the polymer chain active site modification group of this modified polymer can be performed using high performance liquid chromatography (HPLC) or nuclear magnetic resonance spectroscopy (NMR).
[0031]
The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the modified polymer is preferably 10 to 150, more preferably 15 to 80. When the Mooney viscosity is less than 10, sufficient rubber properties such as fracture characteristics cannot be obtained, and when it exceeds 150, workability is poor and it is difficult to knead with the compounding agent.
In the present invention, the modified polymer obtained in this way has an active proton at the terminal, so when carbon black is blended with this, hydrogen bonds with the functional group on the surface of the carbon black, Its dispersibility and reinforcement can be greatly increased. Moreover, when a modifier has the hydrocarbyl oxysilane compound residue represented, for example by the said general formula (II), the affinity with a silica is also large simultaneously.
Therefore, when the modified polymer in the present invention is applied to a rubber composition containing silica and / or carbon black, the interaction with silica and / or carbon black is enhanced, and fracture characteristics, abrasion resistance and It is possible to obtain a modified polymer that can improve low heat build-up at the same time and can exhibit good workability, and a rubber composition and a tire using the modified polymer.
Therefore, the present invention comprises a modified polymer containing a protic functional group having hydrogen as an active proton bonded to nitrogen, oxygen or sulfur at the terminal site of a conjugated diene polymer synthesized by anionic polymerization. But there is.
[0032]
Next, the rubber composition of the present invention contains the above-mentioned modified polymer. Usually, a rubber component containing at least 30% by weight of the modified polymer and 100 parts by weight of silica and / or carbon black. A rubber composition containing 10 to 100 parts by weight is preferred.
This modified polymer may be used alone or in combination of two or more. The rubber component used in combination with the modified polymer includes natural rubber and diene synthetic rubber. Examples of the diene synthetic rubber include styrene-butadiene copolymer (SBR), polybutadiene (BR), poly Examples include isoprene (IR), butyl rubber (IIR), ethylene-propylene copolymer, and mixtures thereof. Further, a part thereof may have a branched structure by using a polyfunctional modifier, for example, a modifier such as tin tetrachloride.
[0033]
The silica is not particularly limited, and can be arbitrarily selected from those conventionally used as reinforcing fillers for rubber.
Examples of the silica include wet silica (hydrous silicic acid), dry silica (anhydrous silicic acid), calcium silicate, aluminum silicate, and the like. Wet silica that is noticeable is preferred. On the other hand, the carbon black is not particularly limited, and any carbon black conventionally used as a reinforcing filler for rubber can be selected and used. Examples of the carbon black include FEF, SRF, HAF, ISAF, and SAF. Carbon black having an iodine adsorption amount (IA) of 60 mg / g or more and a dibutyl phthalate oil absorption (DBP) of 80 ml / 100 g or more is preferable. By using this carbon black, the effect of improving various physical properties is increased, but HAF, ISAF, and SAF, which are excellent in wear resistance, are particularly preferable.
[0034]
In the rubber composition of the present invention, when silica is used as the reinforcing filler, a silane coupling agent can be blended for the purpose of further improving the reinforcing property. Examples of the silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, and bis (2-triethoxy). Silylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyl Trimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthioca Bamoylchitrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxy Silylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyltetra Sulfide, dimethoxymethylsilylpropyl benzothiazole tetrasulfide, etc. are mentioned, but from these points, such as reinforcing effect improvement effect, Scan (3-triethoxysilylpropyl) tetrasulfide and 3-trimethoxysilylpropyl benzothiazolyl tetrasulfide are preferable. These silane coupling agents may be used singly or in combination of two or more.
[0035]
The blending amount of the preferred silane coupling agent varies depending on the type of the silane coupling agent, but is preferably selected in the range of 1 to 20% by weight with respect to silica. If this amount is less than 1% by weight, the effect as a coupling agent is hardly exhibited, and if it exceeds 20% by weight, the rubber component may be gelled. From the viewpoint of the effect as a coupling agent and the prevention of gelation, the preferred amount of the silane coupling agent is in the range of 5 to 15% by weight.
In the rubber composition of the present invention, various chemicals usually used in the rubber industry, for example, vulcanizing agents, vulcanization accelerators, process oils, anti-aging agents, as long as the object of the present invention is not impaired. A scorch inhibitor, zinc white, stearic acid and the like can be contained.
[0036]
The rubber composition of the present invention is obtained by kneading using a kneading machine such as a roll or an internal mixer, and is vulcanized after molding, starting with tire applications, anti-vibration rubber, belt, hose. It can also be used for other industrial products. In particular, it is suitably used as tire rubber, and can be applied to all tire members such as tread rubber (including cap rubber and base rubber), side rubber, ply rubber, and bead filler rubber.
In the present invention, a tire using a rubber composition has good fuel efficiency, particularly excellent fracture characteristics and wear resistance, and the processability of the rubber composition is good. Also excellent.
[0037]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
The physical properties of the polymer were measured according to the following method.
[0038]
<Physical properties of polymer>
The weight average molecular weight (Mw) of the (modified) polymer was measured by gel permeation chromatography [GPC: Tosoh HLC-8020, column: Tosoh GMH-XL (two in series)] Using the differential refractive index (RI), the measurement was performed in terms of polystyrene using monodisperse polystyrene as a standard.
The vinyl content of the butadiene portion of the polymer was determined by an infrared method, and the styrene unit content in the polymer was calculated from the integral ratio of the ¹ H-NMR spectrum.
The Mooney viscosity of the polymer was measured at 100 ° C. using an RLM-01 type tester manufactured by Toyo Seiki Co., Ltd.
[0039]
<Physical properties of vulcanized rubber>
(1) Using a low exothermic viscoelasticity measuring device (Rheometrics), tan δ (50 ° C.) was measured at a temperature of 50 ° C., a strain of 10%, and a frequency of 15 Hz. The smaller tan δ (50 ° C.), the lower the heat generation.
(2) Fracture characteristics (tensile strength)
A strong _{(T b)} at the time of cutting was measured according to JIS K6301-1995.
(3) Abrasion resistance A wear amount of a slip rate of 60% at room temperature was measured using a lambone-type abrasion tester, and the abrasion resistance of Comparative Example 4 was shown as an index. The larger the index, the better.
[0040]
<Mooney viscosity of rubber composition>
The Mooney viscosity [ML _{1 +} 4/130 ° C.] was measured at 130 ° C. according to JIS K6300-1994.
[0041]
Example 1
(1) Preparation of denaturant solution Prepare a 1N cyclohexane solution of N-methylaminopropyltrimethoxysilane (MAPMOS) in a 300 ml pressure-resistant glass container that has been dried and purged with nitrogen so that it is equivalent to MAPMOS. Then, a 3.65N cyclohexane solution of n-butyllithium (BuLi) was added dropwise and stirred well to prepare a solution of the modifier (C).
(2) Production of modified polymer In a 800 ml pressure-resistant glass container dried and purged with nitrogen, 300 g of cyclohexane, 40 g of 1,3-butadiene monomer, 10 g of styrene monomer, 0.43 mmol of ditetrahydrofurylpropane Was added and 0.48 mmol of n-butyllithium (BuLi) was added thereto, followed by polymerization at 50 ° C. for 1.5 hours. The polymerization conversion was almost 100%.
To this polymerization system, the solution of the modifying agent (C) prepared in (1) was added so that N-methylaminopropyltrimethoxysilane was 0.43 mmol, and then a modification reaction was performed at 50 ° C. for 30 minutes. Thereafter, 0.5 ml of a 5 wt% solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol was added to stop the reaction, and then the solvent was removed by steam stripping according to a conventional method. Drying was performed to obtain a modified polymer D. The analytical values of the obtained polymer are shown in Table 1.
[0042]
Example 2 and Comparative Examples 1 and 2
Example 1 (1) In the preparation of the modifier solution, the same procedure as in Example 1 was used except that the modifier of the type shown in Table 1 was used instead of the modifier N-methylaminopropyltrimethoxysilane. Thus, polymers A, B (comparative examples) and E (examples) were obtained. The analytical value of each polymer obtained is shown in Table 1.
Comparative Example 3
In Example 1, the polymer solution C was used in the same manner as in Example 1 except that the modifier solution was not used and (2) in the production of the modified polymer, the amount of BuLi added was 0.38 mmol. Got. The analytical values of the obtained polymer are shown in Table 1.
Example 3
(1) Preparation of denaturant solution Prepare a 1N cyclohexane solution of N-methylaminopropyltrimethoxysilane (MAPMOS) in a 300 ml pressure-resistant glass container that has been dried and purged with nitrogen so that it is equivalent to MAPMOS. After adding a 3.65N cyclohexane solution of n-butyllithium (BuLi) dropwise, a 1N cyclohexane solution of trimethylsilyl chloride (TMSCL) was prepared, added to an equivalent amount to MAPMOS, and stirred well, A solution of denaturant (D) was prepared.
(2) Production of modified polymer The production of the modified polymer of Example 1 was carried out in the same manner as in Example 1 except that the solution of the modifier (D) prepared in (1) was added to the polymerization system. The polymer F was obtained. The analytical values of the obtained polymer are shown in Table 1.
Example 4
Example 1 (1) In the preparation of the modifier solution, the same procedure as in Example 1 was used except that 3-mercaptopropyltriethoxysilane was used instead of the modifier N-methylaminopropyltrimethoxysilane. Thus, a polymer G was obtained. The analytical value of each polymer obtained is shown in Table 1.
[0043]
[Table 1]

[0044]
(note)
Base Mw: weight average molecular weight (Mw) before denaturation reaction
Total Mw: weight average molecular weight (Mw) after the denaturation reaction
Modifier (Comparative Example 1) TTC; Tin Tetrachloride (Comparative Example 2) TEOS; Tetraethoxysilane (Example 1) MAPMOS; N-methylaminopropyltrimethoxysilane to which BuLi was added in an equivalent amount (Example 2) TEOSAA; BuLi N- (3-triethoxysilylpropyl) acetamide added with an equivalent amount (Example 3) MAPMOS &TMCL; N-methylaminopropyltrimethoxysilane added with an equivalent amount of BuLi and trimethylsilyl chloride were reacted (Example 4) MrPTEOS; BuLi 3-mercaptopropyltriethoxysilane added with an equivalent amount of
Examples 5 to 8 and Comparative Examples 4 to 6 (rubber compositions)
Using the polymers A to G obtained in Examples 1 to 4 and Comparative Examples 1 to 3, according to the formulation 1 and the formulation 2 shown in Table 2, the rubber composition of the silica-based formulation and the rubber of the carbon black-based formulation, respectively The composition was prepared by the following method, and the Mooney viscosity of the rubber composition was measured, and vulcanized at 160 ° C. for 15 minutes, and the physical properties of the vulcanized rubber were measured. The results are shown in Table 3.
[0046]
[Table 2]

[0047]
(note)
Carbon black: “Seast KH (N339) (trademark)” manufactured by Tokai Carbon Co., Ltd.
Silica: “Nipsil AQ (trademark)” manufactured by Nippon Silica Kogyo Co., Ltd.
Coupling agent: Degussa silane coupling agent “Si69 (trademark)”, bis (3-triethoxysilylpropyl) tetrasulfide anti-aging agent 6C; N- (1,3-dimethylbutyl) -N′-phenyl- p-phenylenediamine vulcanization accelerator DPG; diphenylguanidine vulcanization accelerator DM; mercaptobenzothiazyl disulfide vulcanization accelerator NS; Nt-butyl-2-benzothiazylsulfenamide
[Table 3]

[0049]
[Table 4]

[0050]
As a result of the above, the modified polymer of the present invention remarkably improves low heat buildup and wear resistance without suppressing the increase in Mooney viscosity and impairing fracture characteristics in both silica-based and carbon black-based formulations. It is recognized that
[0051]
【The invention's effect】
When the modified polymer in the present invention is applied to a rubber composition containing silica and / or carbon black, the interaction with silica and / or carbon black is enhanced, and the fracture characteristics, wear resistance and low heat build-up are improved. At the same time, it is possible to improve the workability. Moreover, according to the method of the present invention, the specific modified polymer having the excellent performance can be easily produced.

Claims (17)

In the method for producing a modified polymer by modifying a diene polymer, (1) General formula (I)
X ¹ −A ¹ −Y ¹ (I)
{Wherein, X ¹ is I groups der monovalent having functional groups reactive with the active site of the diene polymer, and having the general formula (II)

(Wherein, R ¹ and R ² are each monovalent hydrocarbon group having 1 to 18 carbon atoms, n is an integer of 1 to 3, when R ¹ O is more, each R ¹ O is one another The same or different, and when there are a plurality of R ² O, each R ² O may be the same or different.) Hydrocarbyloxysilyl group, carbonyl group, halide, imine, vinyl group , An amide group, a hydrocarbyloxy group, an amino group, and a halogen, Y ¹ is a primary amine and its onium salt, a secondary amine and its onium salt, a primary amide, a secondary amide, Monovalent having at least one protic functional group selected from the group of acetylamide, imino, carbamoyl, (thio) carboxyl group, mercapto group, (thio) alcohol and (thio) ureido Organic group. A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms. }
A compound having a protic functional group selected from the group consisting of a compound represented by the formula: triethoxysilyl compound, trimethoxysilyl compound, methyldiethoxysilyl compound, ethyldiethoxysilyl compound, methyldimethoxysilyl compound and ethyldimethoxysilyl compound (A ) Is reacted with an organic alkali metal or alkaline earth metal compound (B) to obtain a modifier (C) by a pretreatment in which active protons in the protic functional group are alkali metalized or alkali earth metallized. A step of (2) obtaining an intermediate modified product of the polymer by reacting the modifier (C) with the active site of the polymer having an active site, and (3) the metal of the obtained intermediate modified product. And a step of regenerating active protons by removing the metal from the cationization site. Formula (I)
X ¹ -A ¹ -Y ¹ ... (I)
{ Wherein X ¹ is a monovalent group having a functional group that reacts with the active site of the diene polymer, and is represented by the general formula (II)

(Wherein, R ¹ and R ² are each monovalent hydrocarbon group having 1 to 18 carbon atoms, n is an integer of 1 to 3, when R ¹ O is more, each R ¹ O is one another The same or different, and when there are a plurality of R ² O, each R ² O may be the same or different.) Hydrocarbyloxysilyl group, carbonyl group, halide, imine, vinyl group , An amide group, a hydrocarbyloxy group, an amino group and a halogen, and Y ¹ is a primary amine and its onium salt, a secondary amine and its onium salt, a primary amide, a secondary amide, Monovalent having at least one protic functional group selected from the group of acetylamide, imino, carbamoyl, (thio) carboxyl group, mercapto group, (thio) alcohol and (thio) ureido It is a machine group. A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms. }
A compound containing a protic functional group selected from the group consisting of a compound represented by: triethoxysilyl compound, trimethoxysilyl compound, methyldiethoxysilyl compound, ethyldiethoxysilyl compound, methyldimethoxysilyl compound and ethyldimethoxysilyl compound , A diene polymer modifier obtained by reacting with an organic alkali metal or alkaline earth metal compound. In the method for producing a modified polymer by modifying a diene polymer, (1) General formula (I)
X ¹ −A ¹ −Y ¹ (I)
{ Wherein X ¹ is a monovalent group having a functional group that reacts with the active site of the diene polymer, and is represented by the general formula (II)

(Wherein, R ¹ and R ² are each monovalent hydrocarbon group having 1 to 18 carbon atoms, n is an integer of 1 to 3, when R ¹ O is more, each R ¹ O is one another The same or different, and when there are a plurality of R ² O, each R ² O may be the same or different.) Hydrocarbyloxysilyl group, carbonyl group, halide, imine, vinyl group , An amide group, a hydrocarbyloxy group, an amino group, and a halogen, Y ¹ is a primary amine and its onium salt, a secondary amine and its onium salt, a primary amide, a secondary amide, Monovalent having at least one protic functional group selected from the group of acetylamide, imino, carbamoyl, (thio) carboxyl group, mercapto group, (thio) alcohol and (thio) ureido Organic group. A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms. }
A compound having a protic functional group selected from the group consisting of a compound represented by the formula: triethoxysilyl compound, trimethoxysilyl compound, methyldiethoxysilyl compound, ethyldiethoxysilyl compound, methyldimethoxysilyl compound and ethyldimethoxysilyl compound (A ) With an organic alkali metal or alkaline earth metal compound (B), and an active proton in the protic functional group is alkali metalized or alkaline earth metallized, (2) the preliminary A step of obtaining a modifier (D) by further reacting the reaction product of the treatment with an alkylsilyl halide; and (3) reacting the modifier (D) with the active site of the polymer having an active site. A step of obtaining an intermediate modified product of the polymer; and (4) removing the metal from the metallization site of the obtained intermediate modified product. Method for producing a modified polymer, characterized in that comprising the step of playing an active proton Te. Formula (I)
X ¹ -A ¹ -Y ¹ ... (I)
{ Wherein X ¹ is a monovalent group having a functional group that reacts with the active site of the diene polymer, and is represented by the general formula (II)

(Wherein, R ¹ and R ² are each monovalent hydrocarbon group having 1 to 18 carbon atoms, n is an integer of 1 to 3, when R ¹ O is more, each R ¹ O is one another The same or different, and when there are a plurality of R ² O, each R ² O may be the same or different.) Hydrocarbyloxysilyl group, carbonyl group, halide, imine, vinyl group , An amide group, a hydrocarbyloxy group, an amino group, and a halogen, Y ¹ is a primary amine and its onium salt, a secondary amine and its onium salt, a primary amide, a secondary amide, Monovalent having at least one protic functional group selected from the group of acetylamide, imino, carbamoyl, (thio) carboxyl group, mercapto group, (thio) alcohol and (thio) ureido Organic group. A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms. }
A compound containing a protic functional group selected from the group consisting of a compound represented by: triethoxysilyl compound, trimethoxysilyl compound, methyldiethoxysilyl compound, ethyldiethoxysilyl compound, methyldimethoxysilyl compound and ethyldimethoxysilyl compound , A diene polymer modifier obtained by reacting with an organic alkali metal or alkaline earth metal compound and further reacting with an alkylsilyl halide. The modification according to claim 1 or 3, wherein the diene polymer is a polymer obtained by homopolymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and another monomer. A method for producing a polymer. The method for producing a modified polymer according to claim 1 or 3, wherein the metal at the active site of the diene polymer is at least one selected from alkali metals and alkaline earth metals. The method for producing a modified polymer according to claim 5 , wherein the other monomer is an aromatic vinyl compound. The method for producing a modified polymer according to claim 1 or 3, wherein the active site is at the end of the polymer, and at least a part thereof is in an active state. 4. A polymer having an organometallic active site in the molecule is reacted with a protic functional group-containing modifier added in an approximately stoichiometric amount or in excess of the active site. A method for producing the modified polymer according to 1. The method for producing a modified polymer according to claim 5, wherein the conjugated diene compound is 1,3-butadiene or isoprene. The method for producing a modified polymer according to claim 7 , wherein the aromatic vinyl compound is styrene. Modified polymer, characterized in that obtained by the method according to any one of claims 1, 3, 5 to 11 (provided that protic functional groups are selected from primary amine and the group of the onium salt Except modified polymers which are at least one functional group) . The modified polymer according to claim 12 , which has a Mooney viscosity (ML _{1 +} 4/100 ° C) of 10 to 150. A rubber composition comprising the modified polymer according to claim 12 or 13 . The rubber composition according to claim 14 , comprising a rubber component containing at least 20% by weight of the modified polymer according to claim 12 or 13 , and 10 to 100 parts by weight of silica and / or carbon black per 100 parts by weight thereof. The silica to claim 15 rubber composition further comprising a silane coupling agent 0-20% by weight. A tire using the rubber composition according to claim 14 , 15 or 16 .